Battery life is a significant concern for UEs such as smartphones. Broadband radios, large touch screen displays and gigahertz multi-core processors consume a substantial amount of energy. Therefore, power optimization that improves battery life is important to both mobile network operators and smartphone manufacturers. The main components affecting power consumption during voice calls are cellular radio transmitters and receivers including voice codec components. Usually the UE's display is turned off by a trigger from either a proximity sensor or a timer.
Energy saving for cellular radio transmission and reception in the UE can be achieved by turning off transmission and/or reception whenever possible. With the introduction of IP networks, voice over IP (VoIP) systems have been introduced. One implementation of a VoIP system includes a voice over Long Term Evolution (VoLTE) system. In VoLTE systems, one mechanism to manage the operation of transmitters and receivers of the UE is Discontinuous Transmission (DTX) and Discontinuous Reception (DRX). A DTX mechanism uses a silence descriptor (SID) frame to minimize power consumption by the UE when there is a period of voice inactivity. Rather than send “silent” frames, the UE can send a SID frame periodically, e.g., every eight frames, during the period of voice inactivity to reduce transmissions and to reduce power consumption of the UE. While the SID mechanism provides an improvement in power performance, it is desirable to develop apparatuses and methods that can further optimize power consumption at the UE, e.g., by managing adaptively the generation and transmission of SID frames.